Evaluates this XPath expression and returns a result.

  Evaluates this XPath expression and returns a result.
Returns: The result of the evaluation of the XPath expression.For XPath 1.0 results, this object will be of type XPathResult.
Parameters:
- contextNode - The context is context node for the evaluation of this XPath expression.If the XPathEvaluator was obtained by casting the Document then this must be owned by the same document and must be a Document, Element, Attribute, Text, CDATASection, Comment, ProcessingInstruction, or XPathNamespace node.If the context node is a Text or a CDATASection, then the context is interpreted as the whole logical text node as seen by XPath, unless the node is empty in which case it may not serve as the XPath context.
- type - If a specific type is specified, then the result will be coerced to return the specified type relying on XPath conversions and fail if the desired coercion is not possible. This must be one of the type codes of XPathResult.
- result - The result specifies a specific result object which may be reused and returned by this method. If this is specified as nullor the implementation does not reuse the specified result, a new result object will be constructed and returned.For XPath 1.0 results, this object will be of type XPathResult.
Throws:
- XPathException - TYPE_ERR: Raised if the result cannot be converted to return the specified type.
- DOMException - WRONG_DOCUMENT_ERR: The Node is from a document that is not supported by the XPathEvaluator that created this XPathExpression .
NOT_SUPPORTED_ERR: The Node is not a type permitted as an XPath context node or the request type is not permitted by this XPathExpression.